1. Field of the Invention
The present invention relates to a display device comprising a self-light emitting element and a transistor whose channel portion is formed of an amorphous semiconductor or an organic semiconductor.
2. Description of the Related Art
In recent years, a display device comprising a light emitting element has been actively developed. In addition to the advantages of a conventional liquid crystal display device, the light emitting display device has the features such as fast response, superior dynamic display and wide viewing angle. Therefore, the light emitting display device attracts a lot of attention as a next-generation flat panel display.
The light emitting display device comprises a plurality of pixels each having a light emitting element and at least two transistors. In each of the pixels, the transistor which is connected in series with the light emitting element controls light emission or non-light emission of the light emitting element. For the transistors, a polycrystalline semiconductor (polysilicon) with high field effect mobility is used in many cases. The light emitting element has a structure in which an electro luminescent layer is sandwiched between a pair of electrodes. Specifically, an electro luminescent layer is formed on a patterned first conductive layer (a first electrode), and then a second conductive layer (a second electrode) is formed so as to cover the whole surface of electro luminescent layer.